The study was undertaken in order to test a dream-rating scale and to propose some modifications, especially for use in laboratory situations where the effect of a given experimental factor is to be assessed on mental activity in sleep. Dreams collected from normal subjects under EEG monitoring were analysed in detail in order to establish definitions for each rating point of each dimension of the rating scale. The scoring of a second set of dreams by two judges using this scale resulted in an inter-rater agreement significantly above the level of chance agreement.